It is well known that soft drinks typically comprise a combination of soda or carbonated water and an appropriate flavoring syrup. Accordingly, soft drink dispensers typically include both a soda dispensing system and a syrup dispensing system, the soda and syrup being combined at the dispensing head or within the drink receptacle. The invention herein relates particularly to a syrup dispensing system for such soft drink dispensers.
Presently known syrup dispensing systems are of various types. The traditional canister system employs a pressurized canister of syrup, driven by a head of carbon dioxide (CO.sub.2) gas. Such systems are bulky, expensive to establish and maintain, and given to changes in drink consistency resulting from pressure head changes as the canister depletes. Further, "slugs" of gas often appear in the dispensing lines in such CO.sub.2 driven systems. It is further known that various syrups carbonate at different pressures so care must be taken as to the pressure head of CO.sub.2 gas used to drive the various syrups.
Other known syrup systems have incorporated the commonly known "bag-in-box" concept. In such prior systems, a separate vacuum pump is required for each bag-in-box supply, such pumps being costly, unreliable, inaccurate, and given to limitations as to the associated rates at which syrup can be dispensed. Specifically, such bag-in-box systems are given to significant limitations as to the number of stations that can be serviced by a single bag-in-box source and pump. Finally, the pumps in the known bag-in-box systems are typically driven by CO.sub.2 gas, and the operation thereof necessarily wastes this somewhat costly commodity.
While the prior art has not taught systems mixing canister and bag-in-box sources of syrup, it is presently understood that such a mix would typically require that a pressure regulator be associated with each of the syrups in such a system to assure accurate and consistent dispensing.
The prior has also typically failed to employ gravity feed systems. This failure is due, in part, to the fact that it has typically been believed that some type of pressure source or pump must necessarily be associated with each syrup source to assure proper dispensing.
There is a need in the art for a syrup dispensing system which can eliminate the costly and unreliable pressurized canisters of the prior art, as well as the expensive and unreliable bag-in-box systems, requiring a separate pump for each bag-in-box supply. There is clearly a need in the art for a syrup dispensing system which reduces costs, increases accuracy and reliability, assures complete depletion and utilization of syrup from the supply, accommodates faster dispensing rates for high capacity installations, and allows the intermixing of various types of syrup sources in the syrup dispensing portion of a soft drink dispenser.